Natural rubber latex is widely used in the healthcare industry, from surgical gloves to bandages. Because of the unique combination of strength, flexibility, and elasticity of natural rubber, it is typically the material of choice for a variety of medical products. In particular, all known available cohesive bandages are composed at least partly of natural rubber latex. Natural rubber latex is inherently cohesive, meaning that it sticks to itself rather than to other materials. The available adhesive bandages that are entirely free of natural rubber use pressure-sensitive adhesives and are not cohesive.
A small but significant segment of the population develops immediate or delayed allergic reactions to natural rubber. Recently, the United States Food and Drug Administration ruled that all medical devices containing natural rubber latex must be labeled with warnings that the latex can cause allergic reactions. This regulation was issued amid more than 1,700 reports of severe allergic reactions to latex in medical devices that the FDA has received over the past decade. Proteins of natural rubber latex cause IgE-mediated sensitization in 3% to 18% of health care workers and in up to 50% of patients with spina bifida. See Glitter, M., Latex Allergy, Lippincotts Primary Care Practice 1(2):142-151 (1997), which is hereby incorporated by reference. It is believed that plant proteins remaining in products made of natural rubber latex are potential sensitizers. See Posch, A. et al., Characterization and identification of latex allergens by two-dimensional electrophoresis and protein microsequencing, J. Allergy Clin. Immunol. 99(3):385-395 (1997), which is also hereby incorporated by reference. A further disadvantage of using natural rubber latex instead of synthetic latex alternatives is that natural rubber latex degrades, particularly when exposed to petroleum derivative products such as petrolatum, and animal fats. Synthetic latexes, such as polychloroprene, exhibit an enhanced chemical resistance, which natural rubber based products do not possess.
There thus is a real and long-standing need for a cohesive bandage or other product that is free of and thus avoids the allergy-causing proteins found in natural rubber latex and the petroleum-caused degradations of natural rubber latex, yet still possesses the desirable cohesive properties of natural rubber. There is a particular need for such bandages which employ a synthetic elastomeric cohesive that, like natural rubber latex, is water-based and can be employed using procedures similar to those now widely used in connection with the manufacture of natural rubber latex cohesive bandages.